With the global popularity of the digital services, various new services are constantly emerging, however people's demand for traditional service is still ardent. Demands of 2G Age such as telephoning and faxing still exist in the 3G Age. Most of the present 3G terminals are able to support the circuit domain telephone, while VoIP (voice over IP) are generally realized by installing application software in PC.
With the gradual development of VoIP, some manufacturers begin to manufacture hardware devices such as terminal adapter (TA) or VoIP gateway, to facilitate the direct connection between the common home phone and these hardware devices for users. The users could choose to use the circuit domain telephone or VoIP by switching.
However, the call control apparatus which is able to support the circuit domain telephone and VoIP at the same time in the prior art, generally implements supporting the circuit domain telephone and VoIP by means of two foreign exchange stations (FXS), of which one FXS is responsible for the circuit domain telephone and the other is responsible for VoIP. The terminal device like that generally has two RJ11 interfaces, i.e. two telephone line interfaces, and one is dedicated to making the circuit domain telephone call and the other one is dedicated to making the VoIP call. The terminal registers online firstly by the user interface (UI), and then registers in the server of SIP (session initiation protocol) at back-end of the network, thereby the VoIP is available.
The following problems exist in the above-mentioned terminal call control apparatus of prior art: the circuit domain telephone and VoIP must correspond to their respective FXS, and the circuit domain telephone and the VoIP are generally distinguished by two RJ11 interfaces that are different in function, and two SLIC (subscriber line interface circuit) chips are required for implementation.
FIG. 1 is a module interaction diagram of the call control apparatus supporting the circuit domain telephone and the VoIP by using two FXSs and two RJ11 interfaces in the related art, and as shown in FIG. 1, in the design of the two FXSs, an off/on-hook detection module of bottom layer judges which interface an event is from and sends the off/on-hook event and timer event to the circuit domain telephone call control module or VoIP call control module of the upper layer. Specifically, in this way, the circuit domain telephone function is realized by the interface 0 of two interfaces, and the VoIP function is realized by the interface 1 of two interfaces; when judging that an off/on-hook event is from interface 0, the off/on-hook detection module of bottom layer sends the off/on-hook event to the circuit domain telephone call control module of the upper layer; when judging that an off/on-hook event is from interface 1, the off/on-hook detection module of bottom layer sends the off/on-hook event to the VoIP call control module of the upper layer. The support to the circuit domain telephone and the VoIP should be implemented by using the two FXSs and by way of distinguishing two RJ11 interfaces with different functions in this method. Obviously, the implementation of the existing call control apparatus is complicated and costly because of the demand for two SLIC chips.